1 files changed, 55 insertions, 37 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1f48ec871035..e3b3141db13c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -181,7 +181,7 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
         int ret;
         u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
                                   offset * sizeof(u64), sizeof(pdpte));
         if (ret < 0) {
@@ -198,7 +198,7 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
 
         memcpy(vcpu->arch.pdptrs, pdpte, sizeof(vcpu->arch.pdptrs));
 out:
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 
         return ret;
 }
@@ -212,13 +212,13 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
         if (is_long_mode(vcpu) || !is_pae(vcpu))
                 return false;
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         r = kvm_read_guest(vcpu->kvm, vcpu->arch.cr3 & ~31u, pdpte, sizeof(pdpte));
         if (r < 0)
                 goto out;
         changed = memcmp(pdpte, vcpu->arch.pdptrs, sizeof(pdpte)) != 0;
 out:
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 
         return changed;
 }
@@ -278,9 +278,7 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         kvm_x86_ops->set_cr0(vcpu, cr0);
         vcpu->arch.cr0 = cr0;
 
-        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        mutex_unlock(&vcpu->kvm->lock);
         return;
 }
 EXPORT_SYMBOL_GPL(set_cr0);
@@ -320,9 +318,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
         }
         kvm_x86_ops->set_cr4(vcpu, cr4);
         vcpu->arch.cr4 = cr4;
-        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        mutex_unlock(&vcpu->kvm->lock);
 }
 EXPORT_SYMBOL_GPL(set_cr4);
 
@@ -360,7 +356,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                  */
         }
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         /*
          * Does the new cr3 value map to physical memory? (Note, we
          * catch an invalid cr3 even in real-mode, because it would
@@ -376,7 +372,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                 vcpu->arch.cr3 = cr3;
                 vcpu->arch.mmu.new_cr3(vcpu);
         }
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 }
 EXPORT_SYMBOL_GPL(set_cr3);
 
@@ -1211,12 +1207,12 @@ static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
         if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
                 return -EINVAL;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
         kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
 
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
         return 0;
 }
 
@@ -1265,7 +1261,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
             < alias->target_phys_addr)
                 goto out;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         p = &kvm->arch.aliases[alias->slot];
         p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -1279,7 +1275,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 
         kvm_mmu_zap_all(kvm);
 
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
 
         return 0;
 
@@ -1355,7 +1351,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         struct kvm_memory_slot *memslot;
         int is_dirty = 0;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         r = kvm_get_dirty_log(kvm, log, &is_dirty);
         if (r)
@@ -1371,7 +1367,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         }
         r = 0;
 out:
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
         return r;
 }
 
@@ -1565,25 +1561,32 @@ int emulator_read_std(unsigned long addr,
                              struct kvm_vcpu *vcpu)
 {
         void *data = val;
+        int r = X86EMUL_CONTINUE;
 
+        down_read(&current->mm->mmap_sem);
         while (bytes) {
                 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
                 unsigned offset = addr & (PAGE_SIZE-1);
                 unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
                 int ret;
 
-                if (gpa == UNMAPPED_GVA)
-                        return X86EMUL_PROPAGATE_FAULT;
+                if (gpa == UNMAPPED_GVA) {
+                        r = X86EMUL_PROPAGATE_FAULT;
+                        goto out;
+                }
                 ret = kvm_read_guest(vcpu->kvm, gpa, data, tocopy);
-                if (ret < 0)
-                        return X86EMUL_UNHANDLEABLE;
+                if (ret < 0) {
+                        r = X86EMUL_UNHANDLEABLE;
+                        goto out;
+                }
 
                 bytes -= tocopy;
                 data += tocopy;
                 addr += tocopy;
         }
-
-        return X86EMUL_CONTINUE;
+out:
+        up_read(&current->mm->mmap_sem);
+        return r;
 }
 EXPORT_SYMBOL_GPL(emulator_read_std);
 
@@ -1601,7 +1604,9 @@ static int emulator_read_emulated(unsigned long addr,
                 return X86EMUL_CONTINUE;
         }
 
+        down_read(&current->mm->mmap_sem);
         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        up_read(&current->mm->mmap_sem);
 
         /* For APIC access vmexit */
         if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
@@ -1617,11 +1622,14 @@ mmio:
         /*
          * Is this MMIO handled locally?
          */
+        mutex_lock(&vcpu->kvm->lock);
         mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
         if (mmio_dev) {
                 kvm_iodevice_read(mmio_dev, gpa, bytes, val);
+                mutex_unlock(&vcpu->kvm->lock);
                 return X86EMUL_CONTINUE;
         }
+        mutex_unlock(&vcpu->kvm->lock);
 
         vcpu->mmio_needed = 1;
         vcpu->mmio_phys_addr = gpa;
@@ -1636,10 +1644,14 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 {
         int ret;
 
+        down_read(&current->mm->mmap_sem);
         ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
-        if (ret < 0)
+        if (ret < 0) {
+                up_read(&current->mm->mmap_sem);
                 return 0;
+        }
         kvm_mmu_pte_write(vcpu, gpa, val, bytes);
+        up_read(&current->mm->mmap_sem);
         return 1;
 }
 
@@ -1649,7 +1661,11 @@ static int emulator_write_emulated_onepage(unsigned long addr,
                                            struct kvm_vcpu *vcpu)
 {
         struct kvm_io_device *mmio_dev;
-        gpa_t                 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        gpa_t                 gpa;
+
+        down_read(&current->mm->mmap_sem);
+        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        up_read(&current->mm->mmap_sem);
 
         if (gpa == UNMAPPED_GVA) {
                 kvm_inject_page_fault(vcpu, addr, 2);
@@ -1667,11 +1683,14 @@ mmio:
         /*
          * Is this MMIO handled locally?
          */
+        mutex_lock(&vcpu->kvm->lock);
         mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
         if (mmio_dev) {
                 kvm_iodevice_write(mmio_dev, gpa, bytes, val);
+                mutex_unlock(&vcpu->kvm->lock);
                 return X86EMUL_CONTINUE;
         }
+        mutex_unlock(&vcpu->kvm->lock);
 
         vcpu->mmio_needed = 1;
         vcpu->mmio_phys_addr = gpa;
@@ -1718,11 +1737,14 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
 #ifndef CONFIG_X86_64
         /* guests cmpxchg8b have to be emulated atomically */
         if (bytes == 8) {
-                gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+                gpa_t gpa;
                 struct page *page;
                 char *addr;
                 u64 val;
 
+                down_read(&current->mm->mmap_sem);
+                gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+
                 if (gpa == UNMAPPED_GVA ||
                    (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
                         goto emul_write;
@@ -1736,8 +1758,9 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
                 set_64bit((u64 *)(addr + offset_in_page(gpa)), val);
                 kunmap_atomic(addr, KM_USER0);
                 kvm_release_page_dirty(page);
+        emul_write:
+                up_read(&current->mm->mmap_sem);
         }
-emul_write:
 #endif
 
         return emulator_write_emulated(addr, new, bytes, vcpu);
@@ -2118,10 +2141,10 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                 kvm_x86_ops->skip_emulated_instruction(vcpu);
 
         for (i = 0; i < nr_pages; ++i) {
-                mutex_lock(&vcpu->kvm->lock);
+                down_read(&current->mm->mmap_sem);
                 page = gva_to_page(vcpu, address + i * PAGE_SIZE);
                 vcpu->arch.pio.guest_pages[i] = page;
-                mutex_unlock(&vcpu->kvm->lock);
+                up_read(&current->mm->mmap_sem);
                 if (!page) {
                         kvm_inject_gp(vcpu, 0);
                         free_pio_guest_pages(vcpu);
@@ -2247,7 +2270,6 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
         char instruction[3];
         int ret = 0;
 
-        mutex_lock(&vcpu->kvm->lock);
 
         /*
          * Blow out the MMU to ensure that no other VCPU has an active mapping
@@ -2262,8 +2284,6 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
             != X86EMUL_CONTINUE)
                 ret = -EFAULT;
 
-        mutex_unlock(&vcpu->kvm->lock);
-
         return ret;
 }
 
@@ -2447,8 +2467,10 @@ static void vapic_enter(struct kvm_vcpu *vcpu)
         if (!apic || !apic->vapic_addr)
                 return;
 
+        down_read(&current->mm->mmap_sem);
         page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
         vcpu->arch.apic->vapic_page = page;
+        up_read(&current->mm->mmap_sem);
 }
 
 static void vapic_exit(struct kvm_vcpu *vcpu)
@@ -2910,13 +2932,13 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
         gpa_t gpa;
 
         vcpu_load(vcpu);
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, vaddr);
+        up_read(&current->mm->mmap_sem);
         tr->physical_address = gpa;
         tr->valid = gpa != UNMAPPED_GVA;
         tr->writeable = 1;
         tr->usermode = 0;
-        mutex_unlock(&vcpu->kvm->lock);
         vcpu_put(vcpu);
 
         return 0;
@@ -3185,13 +3207,11 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
          */
         if (!user_alloc) {
                 if (npages && !old.rmap) {
-                        down_write(&current->mm->mmap_sem);
                         memslot->userspace_addr = do_mmap(NULL, 0,
                                                      npages * PAGE_SIZE,
                                                      PROT_READ | PROT_WRITE,
                                                      MAP_SHARED | MAP_ANONYMOUS,
                                                      0);
-                        up_write(&current->mm->mmap_sem);
 
                         if (IS_ERR((void *)memslot->userspace_addr))
                                 return PTR_ERR((void *)memslot->userspace_addr);
@@ -3199,10 +3219,8 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
                         if (!old.user_alloc && old.rmap) {
                                 int ret;
 
-                                down_write(&current->mm->mmap_sem);
                                 ret = do_munmap(current->mm, old.userspace_addr,
                                                 old.npages * PAGE_SIZE);
-                                up_write(&current->mm->mmap_sem);
                                 if (ret < 0)
                                         printk(KERN_WARNING
                                        "kvm_vm_ioctl_set_memory_region: "